Heat exchanger

ABSTRACT

The following specification discloses an improved heat exchanger for cooling semi-solids and particularly provides a coolant jacket connector means constructed of stainless steel sheet metal capable of withstanding the expansion and contraction forces caused by the heat transfer from a mash tube to the jackets at the attachment point of the tube and jackets. The connector comprises a pair of oval-shaped sheet metal stampings each being dished to form an upwardly curved edge. The curved edges are mated and welded together to form a rounded hollow elongated body. Each of the pair of oval-shaped dished sheets has a pair of circular openings with a flanged collars punched outwardly from the bottom of the dished sheet remote from the upwardly dished edge. The pair of flanged openings on one side of the connector are dimensioned to fit over the ends of a pair of jackets and the pair of flanged openings on the other side of the connector are dimensioned to fit over adjacent lengths of a twist or turn of the mash tube.

United States Patent De Munnik Mar. 21, 1972 [54] HEAT EXCHANGERNicholas Marie De Munnilt, 450 Walmer Road, Apt. 409, Canada [22] Filed:June 22,1970

[21] Appl.No.: 48,160

[72] inventor:

[52] U.S. Cl .l ..l65/143, 165/83 [51] Int. Cl.. F28f 9/26 [58] FieldofSearch ..l65/l43, 153, 82, 83, 172,

[56] References Cited UNITED STATES PATENTS 3,l7l,478 3/1965 Weiks..l65/l43 2,229,344 l/l94l Schneider ..l65/l43X FOREIGN PATENTS 0RAPPLICATIONS 634,004 10/1 927 France ..l65/82 Toronto, Ontario,

Primary Examiner-Frederick L. Matteson Assistant Examiner'-Theophil W.Streule Attorney-George A. Rolston [57] ABSTRACT The followingspecification discloses an improved heat exchanger for coolingsemi-solids and particularly provides a coolant jacket connector meansconstructed of stainless steel sheet metal capable of withstanding theexpansion and contraction forces caused by the heat transfer from a mashtube to the jackets at the attachment point of the tube and jackets.

The connector comprises a pair of oval-shaped sheet metal stampings eachbeing dished to form an upwardly curved edge. The curved edges are matedand welded together to form a rounded hollow elongated body. Each of thepair of oval-shaped dished sheets has a pair of circular openings with aflanged collars punched outwardly from the bottom of the dished sheetremote from the upwardly dished edge.

The pair of flanged openings on one side of the connector aredimensioned to fit over the ends of a pair of jackets and the pair offlanged openings on the other side of the connector are dimensioned tofit over adjacent lengths of a twist or turn of the mash tube.

6 Claims, 4 Drawing Figures Patented March 21, 1972 Inventor FIG.4

NICHOLAS M. de MUNNIK by: W JWM.

BACKGROUND OF THE INVENTION Heat exchangers are known and used in thedistillery arts to cool the mash to the prescribed temperature.

To affect the cooling process, the mash is passed through pipes orconduits which are surrounded by a coolant material. A tub or bath couldbe used to cool the mash in the pipes, but it is preferred to surroundthe mash conduits with a jacket carrying a flow of coolant materiaLsuchas water or other liquid. A radiator-type cooler having a headerwith amultiplicity of pipes attached to it flowing down into an outlet bodyand all under a pressure system cannot be used, since the mash is notsufficiently liquid to flow evenly through the pipes and an individualpipe could become too readily plugged with the mash or the mash flowunevenly through it, and thereby part ofthe mash would be cooleddifferently than other parts of it. In any event, some pipes would beplugged too easily and the flow of the mash stopped through part of theradiator.

It is known that it isdifficult to surround, in the preferred manner, amash-carrying conduit with a cooling jacket since the expansion andcontraction of the conduit pipes within the jacket cause the joint wherethe conduit pipes emerge from the jacket to rupture and break with theexpansion of the conduit causing leaking of the coolant liquid.Therefore, it has been well known in heat exchangers for the distilleryarts that a jacket must have an expansible joint within it to avoidrupture when the conduit pipe has hot mash introduced to it causing theconduit pipe to expand. One known method of constructing a jacket tosurround a mash-carrying pipe for cooling the mash within the pipe is tofirst space apart lengths of jacket pipe with holes precut andprecontoured in the end surfaces of the jacket pipes to accommodatejacket connectors therebetween. Great care and accuracy is required whenmanufacturing and assembling the known connectors between adjacentjackets in order to maintain the exact required distance between thecenters of the jackets to give the required distance for the U-bendsbeing fitted to the product tubes.

The connectors of the present invention automatically space the producttubes the correct distance apart for abutting the U-bends. The knownreturn or connector pipes are merely joining pipes, and usually ofsmaller cross section than the jacket. In order to withstand theexpansion forces created by the heat of the mash within the tube, it isknown to provide the jacket with an expansible joint in its middlesection comprising a bellows-type of construction which is supposed totake up the force of the expansion against the jacket.

It is known in the construction of cooling jackets in heat exchangers,that when the jacket is made much larger than the surrounded mashcarrying inner pipes, the pressure forcing the flow of the liquidcoolant through the pipes must be very large to ensure that sufficientactual movement of coolant takes place at the surface of the inner pipe,since as is known from hydraulic studies of water movement, a barrierfilm of water caused by the friction of the pipe against the water willbuild up on the surface of the pipe and on the surface of the jacketwith the water flowing between. This surface lamination or sheet ofwater will act as an insulator on the pipe inhibiting the transfer ofthe heat from the mash through the pipe into the water of the jacket.Therefore, it is necessary to make the jacket of a smaller dimension toensure that under the proper pressure conditions, a flow of water isensured past and across the pipes. However, with the construction ofsmaller pipes, the added disadvantage has been found of a hammeringeffect caused by the turbulence and constriction of the water as itturns in the return and connector pipes from one jacket surrounding oneparallel of pipe to another jacket surrounding an adjacent parallel ofmash tube or pipe.

It is, therefore, the principal object of this invention, to design ajacket for a mash-carrying conduit coil of pipes which will ensure thatno rupture or breakage is caused with expansion of the conduit pipesupon introduction of the mash and which will be designed to reduce thefilm effect of the water within the jacket and also reduce the frictionloss caused by the use of many connecting pipes.

When the cooling jacket is an outer pipelike structure surrounding theinner mash-carrying conduit it is necessary that the outer jacket be ofsufficiently greater diameter than the inner conduit pipe to ensure thata smooth flow of cooling fluid is maintained within it, and to avoid theunnecessary turbulence and constriction within the jacket. It has beenfound 'that where the conduit pipe is formed into a twisted, flatserpentine coil form in order to obtain the maximum of spacesaving forthe heat exchanger structure, connector pipes can be used to join thejacket surrounding one lengthof coil of conduit pipe to carry the flowof coolant liquid onward to the next jacket. It has been found that anunnecessarily large amount of turbulence and hydraulic friction takesplace in the connector pipes, thereby causing a decrease in theefficiency of the cooling effect of the water passing through. Thebuildup of friction caused by the use of a -type connection betweenadjacent jackets that abruptly changes the direction of flow of coolantcauses turbulence and decreases the rate of flow, thereby requiring agreater pressure to force the liquid through the system. If alesserpressure is used, the velocity of coolant will decrease, resultingin friction increase in the return pipes, requiring a greater size ofjacket, which obviously cannot be done and still keep the heat exchangerwithin manageable size. The alternative, when velocity remains the sameand the pipes remain the same, is to provide a flow of colder water, orto provide connector return pipes constructed according the presentinvention.

It is the object, then, of the present system, to construct an improvedjacket system for mash-carrying pipes of a heat exchange unit in adistillery by forming the jacket return pipe connectors of expansiblesheet metal which can bear the expansion forces of the pipes carryingthe mash without rupture and which also can conduct the flow of coolantless turbulently from one jacket surround to another.

SUMMARY OF THE INVENTION The above-mentioned objects can be achieved byconstructing a heat exchanger for cooling a flow of material passingthrough a length of tubing by first spacing apart a plurality of jacketpipes in a boxlike serpentine coil, then joining adjacent jacket pipeswith one-half inner side connector of the invention. A length of mashtube is then inserted into each of the jacket members spaced apart bythe one-half dished side of the connector. The other half of theconnector is interfitted over adjacent pairs of lengths of mash tube, tospace the mash tubes concentrically within the coolant jacket. Eachconnector is formed from sheet metal of sufficient size to diminishlaminar friction of the cooling liquid as it enters that portion of thejacket thereby allowing the coolant to flow and change direction morefreely from one conduit surround jacket to the next. After the mashtubes are concentrically held within the jackets by the connectors,U-bend tube members are butt welded to adjacent pairs of mash tubes toform the continuous length of mash-carrying tube. The U-bend ends arenot surrounded by the coolant jacket.

In order to diminish the liability of rupture of the heatedmaterial-carrying conduit from the heat exchange jacket surrounding it,each of the jacket connectors becomes also the joining member forattaching the mash-carrying pipe to the jacket surround in such a mannerthat any expansion of the conduit is transferred to the jacket connectorreturns which absorb the expansion forces and protect the jacket. Theheat transferred to the mash tube from the mash material carried by itwill cause the whole tube to expand, thereby transferring the expansionforces to the whole system of deforming resistant jacket returnconnectors which are made to yield to the force.

In the present invention, the jacket return attachments are formed froma pair of oval-shaped sheet'metal stampings welded together with roundedsurfaces which are yieldable under small degrees of deformation whenattached to surround a section of a tube carrying mash which expandswhen the hot liquid flowing material passes through it. Each ovalshapedside of the jacket connector attachment has stamped out of it a pair ofcircular collars to form circular flanged openings one above the other.The flanged openings are welded to the contacting surface of an upperand lower conduit tube or to an upper and lower jacket surround. Whenthe tube carrying the hot mash expands, the curved surface of theconnector flexes very slightly to take up the expansion. A pair of thesesheet metal members are welded together to form the connector: one sideattaches adjacent jacket members together and the other side attachesadjacent tube members together. Any expansion or contraction of anyportion of the mash tube will be transferred through the tube body toall the connectors thereby spreading the stress and providing longerlife to the structure. The series of return connector attachments acttogether as an accordion or spring to take up the expansion andcontraction forces impressed upon the system during the introduction ofhot mash into the tube of the conduit during the use of the heatexchanger.

Other advantages and benefits of the present invention will becomeapparent from a perusal of the description of a preferred embodiment ofthe invention hereinafter described in detail when taken in conjunctionwith accompanying drawings wherein similar reference numerals refer tosimilar I parts in each figure of the drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a-side elevation of amash-carrying tube formed into a serpentine coil of parallel lengthssurrounded by jacket members and showing adjoining jacket returnconnectors for attachment of the present invention;

FIG. 2 is an end view of the serpentine coil of tubes showing the endviews of the mash tube attached to the jacket connectors;

FIG. 3 is an enlarged view of a jacket connector of the presentinvention shown attached to a pair of jacket pipes and is shownsurrounding the mash-carrying conduit tube or pipe; and

FIG. 4 is a sectional view of the jacket connector of FIG. 3 shownattached around an upper and lower jacket pipe with the mash-carryingconduit passing through and surrounded by the jacket connector andjacket tube or pipe.

DESCRIPTION OF A PREFERRED EMBODIMENT Referring now in detail to thedrawings, numeral 30 is a heat exchanger of the type employed in adistillery operation wherein represents a mash conduit tube formed intoa serpentine coil with individual lengths 10a, 10b, 10c of tube inparallel spaced apart relation and with heat exchange watercarryingcoolant jackets 11 surrounding each of the parallel portions of the coilbundle of tubes 10. A return connector attachment 12 is shown totransfer coolant liquid from one jacket 11a surrounding one length oftube 10a to a jacket 11b surrounding a length of tube 10b next adjacentthe length of tube 10a. An inlet 13 and an outlet 14 are shownpositioned in an upper jacket surround and a lower jacket surroundrespectively. When in operation, a continuous flow of coolant water orother cold liquid is passed into inlet 13 which then flows throughoutthe jacket and emerges from outlet'14.

A plug 15 is provided at each of the unsurrounded U-bend ends of thetubes 10 so that whenever the tube 10 should be plugged with mash, aquick easy access to the interior of each of the lengths of the tube canbe provided, thereby allowing for high pressure steam or the like to beforced through a portion of the tube to clean out the mash and anyaccumulated coatings on the inner sides of the tube. As is well known,having the end of the lengths of the tube open and unsurrounded by thejacket provides a great saving in dismantling and maintenance problemssince the heat exchange jacket does not have to be removed formaintenance to the inner tube.

In FIG. 2, the mash tube 10 is shown with an inlet 16 and an outlet 17which will be connected to suitable piping or tubing (not shown), forcarrying the mash to the heat exchanger unit and for carrying the mashaway from the heat exchanger to the subsequent step in the process. Itwill be seen that the inlet 13 for the coolant is at the bottom of theexchanger unit and the outlet 14 for the coolant is at the top of theunit, whereas the inlet 16 for the mash is at the top of the unit andthe outlet 17 for the mash is at the bottom of the unit. The mashtravels through the exchanger in one direction and the coolant flowsthrough the exchanger counter to the flow of the mash in an oppositedirection which is found to be the best method of obtaining optimumcooling results.

The improved connector 12 of the invention is shown in FIG. 4 and FIG. 3of the drawings. The connector is indicated in FIG. 3 and 4 as numeral12 and is shown in connected position between the section of mash tubing10 and connecting the two adjacent jacket sections 110 and'llb. Thefigure shows the method of attaching the tubes 10, the jackets 11 andthe connector 12.

The connector 12 is made from two separate sheets 18, 19 of oval-shapedstainless steel sheet metal. The sections 18, 19 are shown weldedtogether at seam 20. Each sheet of ovalshaped sheet metal 18, 19 is ofsimilar dimension, but each has different sized openings formed throughthem. The inner side 18 of connector 12 has fonned within it, upper andlower flanged openings having outwardly extending collar flanges 21 and22 which are dimensioned to receive respectively a jacket pipe 11a and ajacket pipe 11b which are disposed one above the other and over a tubesection 10a and tube section 10b. During manufacture, the oval-shapedsheet 18 from which the one side of the connector 12 is formed isstamped into a dished shape having a curved portion 23 extending to itsouter dished edge 24. During the stamping operation of the sheet 18which forms it into the oval-shaped dish, two flanged collars 21, 22 arestamped outwardly from the bottom of the dish to provide the openings asdiscussed above. The whole body of the connector 12 is rounded insurface area. An outer side 19 of the connector 12 is similarly formedin oval-shapeddished appearance with an upwardly extending curvedsurface 25 and a circular outer edge 26. During the stamping operationwhich forms the stainless steel sheet 19 for the outer side of theconnector 12 into a disc-shaped body, two openings are stamped into thelower bottom side of the dished body one above the other of equal sizewith outwardly extending flanged collars 27 and 28 which are dimensionedeach to surround a section of j the turned pipe 100 and 10b.

When the two oval-shaped dished members 18, 19 butt together with theirside edges 24 and 26 mating, the connector body is formed to appear as arounded hollow elongated body 12 having tow large collar portions 21 and22 facing on one side and the two smaller flanged collar openings facingoutwardly on the other side concentrically with the openings on theinner side. FIG. 4 shows how the jacket 11a surrounding a tube length10a is concentrically held in position about the tube by the connector12 when the connector 12 is in position.

The attachment of the jackets 1 1a, 11b with connector 12 is effected byweld 28 and 29 holding collars 21, 22 of side 18 of connector 12 tojackets 11a, 11b respectively. The jacket pipes 11a, 11b are firstsnugly fitted and spaced apart by the collars 21 and 22 of the innerbody portion of the connector 12, thereby to give a good friction fitbefore welding. The outer side portion 19 of the connector 12 is firstbutt welded along seam 20 to side 18 to surround the lengths of pipe 10aand 10b which extend outwardly through collars 27, 28. CoI-. lars 27, 28fit snugly around the tube 10q,, 10b and hold them in concentricsurrounded disposition within jackets 11a, 11b.

The tube lengths 10a, 10b are then welded to collars 27 and 28 l iconduit, a rigid structure is obtained. By having the connector 12formed of stainless, steel and of a shape having curved surfacesthroughout its body, any expansion or contraction forces being createdin either of the jacket pipes 11a, 11b or the conduit tubing must betransferred through the connector body 12 which being itself defonnableand yieldable will take up the contraction forces thereby protecting thewelds, joining the structure together, from rupture.

When the cold water or other liquid is passed through the jacket pipes11, they contract, producing a force at 33, 34. The force does not breakthe welds 28, 29, 31 and 32 which hold the collars 21, 22, 27, 28 of theconnector 12, to the jackets 11 and tubes 10 but is accepted into thebody of the sheet metal forming the connector 12 which is curved todeform and thereby bear the force. In a similar manner, when the heat ofthe mash is transferred to the tube 10, a longitudinal expansion occursto the tube 10 which is transferred to the welds 28, 29, 31 and 32 whichin turn transfer the expansion force to the connector 12. The sheetmetal body of the connector 12 is curved throughout its surface as shownespecially by FIG. 3 and is thereby able to withstand deformation forcescaused by the longitudinal expansion of the tube.

lt will be apparent that heat differential between the tube 10 andjackets 11 at any point in the system will be transferred quicklythroughout the system by the piping, allowing each connector 12 todissipate a portion of the expansion forces. Each connector, in short,becomes a section of-bellows.

It will be clear from the foregoing discussion that the jacketconnectors of the present invention not only attach one jacket pipe toanother to carry the flow of coolant through the exchange as is commonin connectors in the heat exchanger, but the present invention providesthe attachment also to be of itself the method of joining the mash tubeto the connectors. It provides, then the novel dual purpose of jacketconnector and tube attacher for the heat exchange unit.

It will be understood that the present invention can be used mostadvantageously as a heat exchange unit for other types of semisolidmaterial which is being cooled by a liquid or other coolant materialcarried in a jacket to surround an inner semisolid carrying tube orbody.

An added advantage of having the jacket connector returns attached alsoto the tube is that during assembly of the heat exchanger they are usedas spacers to assure that each jacket pipe will be spaced apartconcentrically about a length of mash tube without the necessity ofusing an initial spacer means.

The U-bends of pipe 10 can be attached to the pair of adjacent producttubes 10a, 10b by standard threaded union joints (not shown) or byvitaulac couplings, thereby permitting the U-bends to be removed toclear out the mash ipes. p The whole structure of jackets and connectorscan be erected and assembled together before the product tubes areintroduced, thereby allowing a tremendous saving in time in assemblingand erecting the heat exchanger unit.

The foregoing is a description of a preferred embodiment of theinvention which is given here by way of example only. The invention isnot to be taken as limited to any of the specific features as described,but comprehends all such variations thereof as come within the scope ofthe appended claims.

What I claim is:

1. A heat exchanger comprising a plurality of open-ended spaced apartparallel conduits of substantially equal length;

a plurality of U-bend conduits interconnecting the said open ends ofadjacent ones of said spaced apart parallel conduits to form acontinuous path for flow through said conduits;

parallel jacket pipe means having open ends at each end thereof,surrounding a mid portion of each of said conduits;

jacket pipe connectors extending between adjacent ends of adjacent pairsof said jacket pipe means forming the same into a continuous fluid flowpath in heat exchange relation to said conduits; inner unction means ofpredetermined diameter extending between inwardly directed sides of saidjacket pipe connectors and said jacket pipes for junction therewith;outer junction means of predetermined diameter extending betweenoutwardly directed sides of said jacket pipe connectors and saidconduits for junction therewith, and,

extensible bellows means forming part of said jacket pipe connectors andextending completely therearound and located and spaced outwardly withrespect to said diameters of said inner and outer junction means wherebyto permit relative movement between said inner and outer junction means.

2. A heat exchanger as claimed in claim 1 when said conduits are tubularand wherein said jacket pipe means comprises a plurality of tubularmetal members, each concentrically surrounding a portion of a length ofparallel tubular conduit.

3. A heat exchanger as claimed in claim 1 wherein said conduits aredimensioned to protrude through said outer junction means defined insaid jacket pipe connectors to provide ease of connection for saidU-bends between adjacent pairs of parallel conduits.

4. A heat exchanger as claimed in claim 1 wherein said jacket pipeconnectors comprise a pair of generally ovalshaped sheet metalstampings, said stampings being dished to form outwardly curved edges,said edges being butted one to another and welded to form saidextensible bellows means.

5. A heat exchanger as claimed in claim 1 wherein said jacket pipeconnectors comprise first and second generally oval-shaped dished sheetmetal members butted one to another, each having a pair of circularopenings with flanged collars punched outwardly therefrom forming saidinner and outer junction means, said pair of flanged collars of saidfirst sheet metal member being concentrically aligned with said pair offlanged collars of said second sheet metal member when said first andsecond members are butted one to another.

6. A heat exchanger as claimed in claim 5 wherein said pair of flangedcollars on the first sheet members are dimensioned to snugly fit overthe ends of a pair of adjacent jacket pipe means and wherein said pairof flanged collars on the second sheet members are dimensioned to fitover adjacent lengths of conduit, thereby locating the sameconcentrically within their respective jacket pipe means.

1. A heat exchanger comprising a plurality of open-ended spaced apartparallel conduits of substantially equal length; a plurality of U-bendconduits interconnecting the said open ends of adjacent ones of saidspaced apart parallel conduits to form a continuous path for flowthrough said conduits; parallel jacket pipe means having open ends ateach end thereof, surrounding a mid portion of each of said conduits;jacket pipe connectors extending between adjacent ends of adjacent pairsof said jacket pipe means forming the same into a continuous fluid flowpath in heat exchange relation to said conduits; inner junction means ofpredetermined diameter extending between inwardly directed sides of saidjacket pipe connectors and said jacket pipes for junction therewith;outer junction means of predetermined diameter extending betweenoutwardly directed sides of said jacket pipe connectors and saidconduits for junction therewith, and, extensible bellows means formingpart of said jacket pipe connectors and extending completely therearoundand located and spaced outwardly with respect to said diameters of saidinner and outer junction means whereby to permit relative movementbetween said inner and outer junction means.
 2. A heat exchanger asclaimed in claim 1 when said conduits are tubular and wherein saidjacket pipe means comprises a plurality of tubular metal members, eachconcentrically surrounding a portion of a length of parallel tubularconduit.
 3. A heat exchanger as claimed in claim 1 wherein said conduitsare dimensioned to protrude through said outer junction means defined insaid jacket pipe connectors to provide ease of connection for saidU-bends between adjacent pairs of parallel conduits.
 4. A heat exchangeras claimed in claim 1 wherein said jacket pipe connectors comprise apair of generally oval-shaped sheet metal stampings, said stampingsbeing dished to form outwardly curved edges, said edges being butted oneto another and welded tO form said extensible bellows means.
 5. A heatexchanger as claimed in claim 1 wherein said jacket pipe connectorscomprise first and second generally oval-shaped dished sheet metalmembers butted one to another, each having a pair of circular openingswith flanged collars punched outwardly therefrom forming said inner andouter junction means, said pair of flanged collars of said first sheetmetal member being concentrically aligned with said pair of flangedcollars of said second sheet metal member when said first and secondmembers are butted one to another.
 6. A heat exchanger as claimed inclaim 5 wherein said pair of flanged collars on the first sheet membersare dimensioned to snugly fit over the ends of a pair of adjacent jacketpipe means and wherein said pair of flanged collars on the second sheetmembers are dimensioned to fit over adjacent lengths of conduit, therebylocating the same concentrically within their respective jacket pipemeans.